Method of making granules



EXAMINER 1 6 8 9 cross REFEREMCE Patented Apr. 13, 1948 .METHOD OF MAKING GRANULES Charles W. Cuno, Wilmington, 111., assignor to The Lehon Company, a corporation of Illinois N 0 Drawing. Application January 28, 1944,

Serial No. 520,135

12 Claims. (Cl. 117-100) Much efiort has been devoted to the development of granules of a character suitable for surfacing composition roofing material. It is, of course, necessary that such granules be able to terial, such as crushed slag, non-porous vitreous granules, and the like can be used although the results are not as satisfactory.

In place of the magnesium fluosilicatg other 2 Silicate w or some solublame;

such as cgppgr, manganese a and g ggehmmsilin es can be used although at the present time, the cost of these are commerfilling the pores and making harder granules.

That is, by adding the fluosilicate solution first,

it penetrates into the pores of the granules and draws the cement or lime into the pores so that soluble fiuosilicates, such as afii'r'i'6nlnm flliu= 55 a denser, harder, less porous material is formed stand severe weathering. At the present time, cially prohibitive. In place of th lime, may be commercial granules are usually either natural used white Portland cement or ordinary Portland mineral products such as crushed slate, ceramic cement, or if the cost should become reasonable or semi-ceramic products. These latter are subother suitable metallic bases such as sodium hy- J'ect to the objection of high cost and, the former, droxide or alkaline earth hydroxides, such as to various objections including limited choice of barium hydroxide or strontium hydroxide; the color, object being to produce .in situ a, more or less Numerous substitutes have been proposed. insoluble fluosilicate by reaction of the more sol- Some of them have proved unsatisfactory beuble magnesium fluosilicate with other substances cause of absorption of moisture and crumbling which will produce the less soluble fiuosilicates. upon freezing. Some have been subject to the 15 y Suitable m tallic base is meant a one which is efiect known as blooming because of containing soluble in water and reacts with the magnesium a substance su h as li wh h would be di fiuosilicates to form a substantially insoluble solved by rain and, reacting with the carbon cate dioxide of the air, leave a discoloring insoluble y Suitable pigment may be d Such as White coating. Some lacked hardness so that (Killers, y ed and black ferric they were crushed by the weight of a man walko ides, or an inert green Oxide, e ing on the roof. There may be some which, h preferred p portions by wei ht are six though free from the foregoing objections, would pa O S ag to one-hajj tg onepart of lime or have been too expensive for commercial use. cement ahd gjgt Parts megnesilim fluo- According to the present invention, all of these silicate. The amoufit' omel' is not critical but difiiculties are substantially overcome. The raw a at ated solution of magnesium fluosilicate is material cost of the preferred embodiment is very P r a r y wide variations may be made low, the manufacturing cost is low, the resultin these P oportions. For examp e, t hydrated ing gramme is hard, does not, deteriorate apprelime may vary at least from one-half 120 one and ciably in weathering, and is not objectionable one-half P nd t ment at least from fr m t standpoint of producing bloom three-fourths to one and one-half parts. Theocording to the preferred process even the cost of t y Sufiicieht s um fluosilicate should the pigment is cut, in half as cgmpared to the be added 130 neutralize and react with all the free l t prior processes, lime and any other substance reacting with the In its preferred form, the invention consists in fluosilicate. In practice a small excess of fluomixing ex 1 r r with a saturated siliceteis preferred. solution of 8 adding lime e P p tion Of pigments added will depend mhm l wm and then after, i upon the color and brightness desired, generally adding th pi en The mixture is then one-fourth to one-half part being suitable. Tests stirred continually until danger of adhesion is 40 have indicated that for a given visual e o l passed and preferably maintained in a stream of approximately f e p t is r q ed Warm or hot air, until substantially dry, this hat would be required if it were mixed initially taking only about thirty (30) minutes or less, with the Portland cement. Of course the pig- The expanded slag is readily obtainable. It is ment is omitted if a white or cement colored produced by cooling the molten slag in the presgranule is desired. ence of water or steam. Other granular material When, in accordance with this invention, the I may be used, preferably porous material such as magnesium fluosilicate solution is added to the i cinders or porous ceramic materials. Expanded porous granules first and then the lime or lime l slag is preferred because of its great porosity and bearing material, the effect is to produce the callow cost. Non-porous material or less porous macium fluosilicate in situ well within the pores,

cement.

than would be the case if the cement or lime were added to a dry granule, or when water is added first instead of the fiuosilicate;

It is believed that the major reaction is that of the fluosilicate and the lime to produce calcium fluosilicate which is substantially insoluble. But other fiuosilicates, fluorides and silicates are undoubtedly also formed together with magnesium hydroxide; 'vvhichis much less soluble than lime and which does not produce an objectionable bloom. In the case of Portland cement, the lime for this reaction is obtained from the Portland cement. That magnesium fluosilicate acts to accelerate the setting of the Portland cement and to harden it is known to prior art. For example, a magnesium fluosilicate solutionhasl iggg used to wash a cefifntmuor taharden itr'iAls'o vars smallquamtItiBEQaYBIbeemmixQd with the mix the cement proportions such as are now contemplated which are sufficient to use up all of the free lime available from the cement. This result is made possible by applying the fluosilicate solution to the granules first, so that the reaction takes place in situ.

From the foregoing it is seen that a granule has been developed which is weatherproof and color fast, light in weight, inexpensive, and hard enough so that a surfacing of such granules or roofing will be able to withstand the weight of a worker walking thereon. It has been observed from slicing an expanded slag granule at least an eighth of an inch in diameter treated in accordance with this invention that the pores are substantially filled with the precipitate throughout the granule, thus showing that the penetration is at least one-sixteenth inch from the surface.

I claim:

1. The method of making hard weatherproof granules for covering material comprising the steps of mixing expanded slag granules with a solution of magnesium fluosilicate in direct contact with the granules, adding thereto and mixing therewith a substance providing lime for reaction with said magnesium fluosilicate, and thereafter adding and mixing therewith a pigment, thereafter continuing agitation of the coated granules until the coating has sufficiently set to prevent adhesion of the granules to one another.

2. The method of making hard weatherproof granules for covering material comprising the steps of mixing porous granules with a solution of magnesium fluosilicate in direct contact with the granules, adding thereto and mixing therewith a substance providing lime for reaction with said magnesium fluosilicate, and thereafter adding and mixing therewith a pigment, thereafter continuing agitation of the coated granules until the coating has sufliciently set to prevent adhesion of the granules to one another.

3. The method of making hard weatherproof granules for surfacing covering material comprising the steps of mixing porous granules with a solution of a soluble fluosilicate in direct contact with the granules, adding thereto and mixing therewith a substance providing lime for reaction with said fiuosilicate, thereafter adding and mixing therewith a pigment, and thereafter continuing agitation of the coated granules until the coating has sufliciently set to prevent adhesion of the granules to one another.

4. The method of making hard weatherproof granules for surfacing covering material comlt has not been possible, howverftd prising the steps of mixing porous granules with a solution of a soluble fiuosilicate in direct contact with the granules, adding thereto and miidng therewith a substance providing lime for reaction with said fiuosilicate, and thereafter continuing agitation of the coated granules until the coating has sufficiently set to prevent adhesion of the granules to one another.

5. The method of making hard weatherproof granules for surfacing covering material comprising the steps of mixing granules with a solution of magnesium fluosilicate in direct contact with the granules, adding thereto and mixing therewith a substance providing lime for reaction with said magnesium fluosilicate, thereafter adding and mixing therewith a pigment, and thereafter continuing agitation of the coated granules until the coating has sufliciently set to prevent adhesion of the granules to one another.

6. The method of making hard weatherproof granules for surfacing covering material comprising the steps of mixing granules with a solution of magnesium fluosilicate in direct contact with the granules, adding thereto and mixing therewith a substance providing lime for reaction with said magnesium fluosilicate, and thereafter continuing agitation of the coated granules until the coating has sufficiently set to prevent adhesion of the granules to one another.

7. The method of making hard weatherproof granules for surfacing covering material comprising the steps of mixing granules with a solution of a fluosilicate in direct contact with the granules, adding thereto and mixing therewith a substance providing a. soluble metallic base which will react with said fluosilicate to produce an insoluble fluosilicate, and thereafter continuing agitation of the coated granules until the coating has sufficiently set to prevent adhesion of the granules to one another.

8. The method of making hard weatherproof granules for surfacing covering material comprising the steps of mixing granules with a solution of a fiuosilicate in direct contact with the granules, adding thereto and mixing therewith a substance providing a soluble metallic base which will react with said fiuosilicate to produce an insoluble fluosilicate.

9. The method of making hard weatherproof granule's for surfacing covering material comprising the steps of mixing granules with a solution of magnesium fluosilicate in direct contact with the granules, adding thereto and mixing therewith Portland cement for reaction with said magnesium fluosilicate, and thereafter continuing agitation of the coated granules until the coating has sufliciently set to prevent adhesion of the granules to one another.

10. The method of making hard weatherproof granules for surfacing covering material comprising the steps of mixing granules with a solution of a fluosilicate in direct contact with the granules, adding thereto and mixing therewith Portland cement for reaction with said fluosilicate to produce an insoluble fluosilicate, and thereafter continuing agitation of the coated granules until the coating has sufficiently set to prevent adhesion of the granules to one another.

11. The method of making hard weatherproof granules forsurfacing covering material comprising the steps of mixing granules with a solution of a fluosilicate in direct contact with the granules, adding thereto and mixing therewith Portland cement for reaction with said fluosilicate to produce an insoluble fluosilicate.

1, 06 8 9 eaoss aerggzstce min-1mm 6 1 12. The method of making hard weatherproof granules for surfacing covering material com- ITED STATES PATENTS prising the steps of mixing bare porous granules with a. solution of a. soluble fluosilicate, adding Number Name Date thereto and mixing therewith a substance pro- 5 2,057,677 Gundlach Oct. 20, 1936 viding lime for reaction with said fiuosilicate, 2,061,246 c ols Nov. 17, 1936 thereafter adding and mixing therewith a, pig- 2,114,692 Ward Apr. 19, 1938 ment. and thereafter continuing agitation of the 2,215,600 eazy se t. 24, 1940 coated granules until the coating has sumciently 2,294,523 Veazy Sept. 1, 1942 set to revent adhesion of the ranules to one 10 another? g FOREIGN PATENTS C s CUNO' Number Country Date REFERENCES crmn 1 Germany 1940 The following references are of record in the 15 file of this patent: 

